test: Add uint256 string parse tests

Author: MarcoFalke

src/test/uint256_tests.cpp

@@ -279,6 +279,34 @@ BOOST_AUTO_TEST_CASE( operator_with_self )
     BOOST_CHECK(v == UintToArith256(uint256S("0")));
 }
 
+BOOST_AUTO_TEST_CASE(parse)
+{
+    {
+        std::string s_12{"0000000000000000000000000000000000000000000000000000000000000012"};
+        BOOST_CHECK_EQUAL(uint256S("12\0").GetHex(), s_12);
+        BOOST_CHECK_EQUAL(uint256S(std::string{"12\0", 3}).GetHex(), s_12);
+        BOOST_CHECK_EQUAL(uint256S("0x12").GetHex(), s_12);
+        BOOST_CHECK_EQUAL(uint256S(" 0x12").GetHex(), s_12);
+        BOOST_CHECK_EQUAL(uint256S(" 12").GetHex(), s_12);
+    }
+    {
+        std::string s_1{uint256::ONE.GetHex()};
+        BOOST_CHECK_EQUAL(uint256S("1\0").GetHex(), s_1);
+        BOOST_CHECK_EQUAL(uint256S(std::string{"1\0", 2}).GetHex(), s_1);
+        BOOST_CHECK_EQUAL(uint256S("0x1").GetHex(), s_1);
+        BOOST_CHECK_EQUAL(uint256S(" 0x1").GetHex(), s_1);
+        BOOST_CHECK_EQUAL(uint256S(" 1").GetHex(), s_1);
+    }
+    {
+        std::string s_0{uint256::ZERO.GetHex()};
+        BOOST_CHECK_EQUAL(uint256S("\0").GetHex(), s_0);
+        BOOST_CHECK_EQUAL(uint256S(std::string{"\0", 1}).GetHex(), s_0);
+        BOOST_CHECK_EQUAL(uint256S("0x").GetHex(), s_0);
+        BOOST_CHECK_EQUAL(uint256S(" 0x").GetHex(), s_0);
+        BOOST_CHECK_EQUAL(uint256S(" ").GetHex(), s_0);
+    }
+}
+
 BOOST_AUTO_TEST_CASE( check_ONE )
 {
     uint256 one = uint256S("0000000000000000000000000000000000000000000000000000000000000001");